Repelling a switch

How can declarer increase his chances that the opponents do not find the winning switch?

That was the issue I had to face on Board 20 of the Saturday evening, July 23 session of a two-session regional pairs at the Toronto NABCs.

West ♠ 985 ♥ AK3 ♦ KQ ♣ JT876

East ♠ Q2 ♥ JT9 ♦ A653 ♣ KQ42

As West, I opened 1♣ and rebid 1NT over partner’s 1♦ response.  Partner raised to 3NT and North led the ♥5.

Clearly, I need to knock out the ♣A.  I was fortunate to have escaped a spade opening lead.  How can I best continue that good fortune when I must let the opponents in once again?

I played a heart from dummy and South followed with the ♥6 (presumptively right side up count).  I won the first trick with the ♥K, trying to look like a man with AK tight.  I led a club from hand and North hopped with the ♣A, his partner playing the ♣3.

At the table, not only did I escape a spade switch, but when North returned a second heart (the two), I was back to owning three heart tricks, recovering the trick I intentionally gave away at Trick 1!  Three hearts, three diamonds, and four clubs for +630 was worth 31.5 mps (on a top of 33, I think).

The whole hand:

Dealer: Vul:	North ♠ A764 ♥ Q8752 ♦ J92 ♣ A
West ♠ 985 ♥ AK3 ♦ KQ ♣ JT876		East ♠ Q2 ♥ JT9 ♦ A653 ♣ KQ42
	South ♠ KJT3 ♥ 64 ♦ T874 ♣ 953